Linter: doesn't respect indent size

After changing `indent_size` to 2 in my `.editorconfig`, I noticed that the formatter wouldn't format certain lines that the linter would flag. It looks like the max line length calculation of the linter assumes the indent size is 4 rather than using the same indent size config that the formatter uses.

Here's a basic GDScript example that the linter flags as too long even though it should be within the max line length limit. This is supported by the fact that the formatter does not format the line since it respects the `indent_size`.

```gdscript
func test() -> Array[String]:
# This line is incorrectly flagged by the linter when indent_size is 2.
return ["echo", "echo", "echo", "echo", "echo", "echo", "echo", "echo", "echo", "echo", "echooo"]
```

The offending line looks to be https://github.com/GDQuest/GDScript-formatter/blob/29e2dc993b2ed746f50dae594357e020f7ccc3b9/src/linter/rules/max_line_length.rs#L24

The indent is increments by a hard-coded 4.

src/linter/rules/max_line_length.rs:24 から始めて、formatter が indent_size をどのように読み取るかを追跡します。indent_size 2 を使用する、提供された GDScript の例と linter のインデント計算を比較します。linter がその行を報告しなくなり、他のインデント設定に対する max-line-length の動作が維持されれば完了です。

索引モデルが issue の本文から書いたものです。